9.6 Window Technique

Now we can look at the problem that arises when a client needs to send large amounts of data. The client (or server) can send data to the other side without its reception being confirmed up to an amount that is called a window (or WIN in short). The WIN determines the opposite (destination) site of connection.

In Figure 9.16, let us imagine that the client has established a connection with the server and they have mutually agreed on an Maximum Segment Size (MSS) of 1 K (or 1024 B) and a mutual window size of 4 K (or 4096 B).

Figure 9.16: Window technique

The window technique is easier to understand from the figure above:

• The client begins transmitting data and sends segments 1, 2, and 3.
• The server returns a confirmation (segment 4) from the server that confirms segments 1 and 2.
• The client in return sends segments 5, 6, and 7, but the server has not had enough time to process the data and its buffer has been exhausted.
• Segment 8 therefore confirms that segments 3, 5, 6...